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Posted to common-user@hadoop.apache.org by jiang licht <li...@yahoo.com> on 2010/04/21 21:19:13 UTC

confusion about dfs.replication

A trivial question. So, here it is: according to the hadoop documentation,
 "dfs.replication" defines the number of replications of a block. So, if
 "dfs.replication" is set to N, then that means each file has actually 
(N+1) copies. Is this correct?

Thanks,

Michael


      

Re: confusion about dfs.replication

Posted by jiang licht <li...@yahoo.com>.
Thanks Eric. I found this out simply from viewing blocks and their locations in UI (maybe some commands will also report this, forgot which one).

Best regards,

Michael

--- On Wed, 4/21/10, Eric Sammer <es...@cloudera.com> wrote:

From: Eric Sammer <es...@cloudera.com>
Subject: Re: confusion about dfs.replication
To: common-user@hadoop.apache.org
Date: Wednesday, April 21, 2010, 2:20 PM

Just N copies. There's no notion of the "original" copy of the data.

On Wed, Apr 21, 2010 at 3:19 PM, jiang licht <li...@yahoo.com> wrote:
> A trivial question. So, here it is: according to the hadoop documentation,
>  "dfs.replication" defines the number of replications of a block. So, if
>  "dfs.replication" is set to N, then that means each file has actually
> (N+1) copies. Is this correct?
>
> Thanks,
>
> Michael
>
>
>



-- 
Eric Sammer
phone: +1-917-287-2675
twitter: esammer
data: www.cloudera.com



      

Re: confusion about dfs.replication

Posted by Eric Sammer <es...@cloudera.com>.
Just N copies. There's no notion of the "original" copy of the data.

On Wed, Apr 21, 2010 at 3:19 PM, jiang licht <li...@yahoo.com> wrote:
> A trivial question. So, here it is: according to the hadoop documentation,
>  "dfs.replication" defines the number of replications of a block. So, if
>  "dfs.replication" is set to N, then that means each file has actually
> (N+1) copies. Is this correct?
>
> Thanks,
>
> Michael
>
>
>



-- 
Eric Sammer
phone: +1-917-287-2675
twitter: esammer
data: www.cloudera.com